Faulty circuit alarm



Feb. 26, 1957 s. M. HAMMER FAULTY CIRCUIT ALARM Filed March 18, 1954 INVENTOR f/fnev/JM /%m/?7e/' Mal am, 3731M & 0%(

ATTORNEY United States Patent 9 i FAULTY CIRCUIT ALARM Si'gwalii M. Hammer, Independence, Kans., assignor-to Sinclair Research Laboratories, Inc, Harvey, iii, a

corporation of Delaware Application March 18, 1954, Serial No. 417,172

4 Claims. (Cl. 340-251) My invention relate'sto alarming devices and more-parti'cularly provides a system for actuating an alarm to indicate failure of automatically intermittently or periodi-' 'cally actuated remotely located electrical equipment.

The failure of automatically operated illuminating lamps-such as beacon and Warning lamps used on radio "or other towers requires in many instances the produc- 'tion of an alarm signal to indicate such failure to an attendant located at some remote point. It is often desirable where different groups of lights are employed at a given location to produce an alarm signal indicating the failure as-occurrin'g in one particular group of lights or toindic'ate failure of the immediate power circuit serving the lights in order that the remotely located attendant can be properly informed as to the nature of the equipment which has failed and thus indicate the necessary replacement p'arts'as well as the urgency of the failure.

I hayefound that in automatically and intermittently or periodically operated remote equipment automatic.

alarm signal operation can be obtained by a system utilizing'del'ayed'action, thermally operated, circuit controlling devices wherein a normally open first thermal delay relay is actuated to close an independent alarm circuit in response to application of operating potentials to the remotely located-electrical system, and wherein a normally closed'second thermal delay relay, having-a shorter period of actuation-than the first relay device, is actuatedfin response to the flow of current to the remotely located electrically operated device to open the independent alarm circuit by connection of its switch contacts in series with the switch contacts of the first relay device.

I am 'aware that heretofore thermally sensitive circuit breaking devices have been utilizedto defect lamp failure at remotely located lamp installations-by positioning "such devices in the proximity of the lamps to be monitored to cause the devices to operate in response to the presence or absence of heat r'adiatedby the'lamp's. Such thermally sensitive contacting devices are particularly subjectt'othe disadvantage that their location in the proximity of'the =lampftobe monitored often makes them relatively inacces'sible for servicing and requires an additional electric "le'ad' tobe Wired in with power lines tothe lai'n'p. 'S uch contactors are also limited to usage in detection of 'failtire of remotely located electrical equipment which operate at relatively high temperatures, such as lamps, and cannot beused to'd'et'ect failure of relatively cold running electrical equipment.

It is'a particular object of my invention to providea'der tecting and alarm circuit actuating device for remotely located electrical devices which is not dependent on 'th'e heat radiated by the electrical device monitored and which can therefore 'be remotely located from the device monitored. N

The system of my invention is particularly useful in the case of radio beacon andside lamps which are actuated by a photo-electric unit atnighttimeaiidwhich remain unactuated during daytime. The 'u'sc ofa normally open slower operating delayed action'alar m circuit con- 2,783,458 Patented Feb. 26, 1957 trolling device operating in response to the closure of the power circuit by the photo-electric element in series with a normally closed faster'operating delayed action alarm circuit controlling device operating in response to the flow or current to the beacon and side lamps prevents accidental actuation of the alarm circuit as the photoelectric ele'ment closes the power circuit connection, and yet permits the alarm circuit to be used upon lamp failure. Moreover, in radio tower beacon lamps where a flas herfunit is utilized, the faster acting thermally operated delay relay can be selected to have a period of operati e "delay exceeding the period of operation of the flasher iinitan'd thus operate independently of such relatively rapid periodicactuation and deactua'tionof thereni o'tely located warning lamps. I

The system of my invention also contemplates a plurality of the faster acting thermal operated delay relays operated in parallel banks connected to control a plurality era-1am circuits'all having a commonground circuit contreated in "a series through the "slower acting thermally o'perated delay relay. I can thereby provide separate alarm c'irfc'iiits as required, for example, for different groups of lamps, 'or lamps having'diflierent wa'ttages or ditferent operating characteristics.

I have found, furthermore, that it is particularly 'desirablef to connect the alarm circuits through a common gr'oiih'd' to the neutral line in the power circuit leading. to the r motel located device, placing an control equip- "iiicnt ro'r the 'rei'note installation in the connection to the 'hb't-'powcr liiie. Failure "of overload circuit breaker devices or f'usesin the hot read to the 'l'emotelyloeiited device can thus also be detected and indicated over the ztlz'i'rm circuits. Since the slower actin'g relay is normally open, indication of a circuit breaker or fuse failure is obtamed by paralleling the slower relay switch contacts by the switch contacts of a normally closed faster acting thermally operated delay relay, which .upon actuation closes the alarm circuit, but which is operatively connected tothe incoming power line and hence remains open except upon failure of overload circuit breakers, or upon power line failure. I

The drawing schematically illustrates the application {of the ala'r'm system of my invention to an automatically operated, remotely located, radio tower having flashing beacon and steady'side warning lamps. I

In the accompanying drawing, the reference number 1 indicates a radio tower having a pair of beacon lamps 2 and 3 and having four side lamps 4, 5, 6, and 7. Electrical power lines 8 and 9 supply power to the installation, line 8 being the neutral line. I

' A photo-electric unit, diagrammatically shown in the drawing-and indicated by the reference number 10, is utilized to actuate the beacon and side lamps of tower during the nighttime by closing a circuit controlling device connecting the beacon and side lamps to power line 9 through an over-load circuit breaker 11. Connection to neutral line 8 at the installation is to post 1211 of an eleven post terminal strip located in cabinetneonvenienu positioned near the baseof the tower. Terminal post 12b is connected internally to terminal 'post 1-221 and is connected externally as a common ground lead to all six beacon lamps by line 14.

Connection between hot power line 9 and terminal pest 12c in cabinet 13 is made through photo-electric unit 1011s indicated above and through an automatic flasher uiiit; ialsodialgrammatically illustrated in the drawing, and indicated by the reference number 15. Flasher unit 15 is designed to open and close the connection between phage-tube unit 10 and terminal post' 12c at a relatively rapid periodic rate of, forexample, one cycle every five seconds. A second connection from photo-unit 10, bridging 'fias'her unit 15, is brought to terminal post 12d in cabinet 13 and a connection from circuit breaker 11 is brought directly to terminal post 122 in cabinet 13.

Terminal post 12c, which is externally connected through flasher unit 15, is connected internally to terminal post 12 through an adjustable resistor 16, and internally connected to terminal post 12g through an ad} justable resistor 17. Terminal post 12d, which is externally connected to photo-unit and bridges flasher unit 15, is internally connected to terminal post 1271 through adjustable resistor 18 and is internally connected to terminal post 12i through adjustable resistor 19.

As before noted each of beacon lamps 2 and 3 and each of side lamps 4, 5, 6 and 7 is connected to terminal post 12b through a common ground lead 14. The hot connection to beacon lamp 2 is made to terminal post 12;. The hot lead connection 21 to beacon lamp 3 is made to terminal post 12g. Side lamps 4 and 5 are connected in parallel and are provided with a hot lead connection 22 to terminal post 12h. Similarly, side lamps 6 and 7 are connected in parallel to terminal elemeat 12: through hot lead connection 23.

The preceding description of the tower lamp powering circuits is conventional with the exception of the inclusion of adjustable resistors 16, 17, 18 and 19 located in series with hot leads 20, 21, 22 and 23 to the beacon and side lamps. In the device shown in the drawing, 1 employ'six' thermally operated delay relays, e. g., circuit controlling devices having a heating filament which upon energization causes actuation of a bi-metallicswitch wherein operation of the bimetallic switch member occurs with a certain time delay after enengization of the heating filament. Such time delays are accurately calculable, and thermally operated delay relays are commercially available in a variety of filament voltages and delay periods.

In the system shown in the drawing I employ a first thermally operated delay relay 24 having a filament 24A designed for energization by a voltage equal to that of the voltage on power lines 8 and 9. Relay 24 isprovided with a normally open bi-metallic contact member 24b which closes with contact member 24c 120 seconds after energization of filament 24a in the illustrated case. Relay 24 is commercially available under the designation 'l15NOl20 for 110 to 120 volts filament voltage.

The second thermally operated delay relay 25 has a filament 25a with a similar voltage rating to filament 24a. Relay 25 has a bi-metallic movable contact member 25b which is normally closed with fixed contact 250' but which opens after energization of filament 25a by the proper voltage after a delay, in the illustrated case, of approximately seconds. For 110 to 120 volts service relay 25 is commonly available under the designation 1l5C30.

Four additional thermally operated delay relays are employed. These are designated by the reference numerals 26, 27, 28 and 29. These relays are identical and have heating filaments 26a, 27a, 28a and 29a, respectively, which are designed for a relatively low applied voltage, in the illustrated case about 2 /2 volts. Each of relays 26, 27, 28 and 29 has a movable bi-metallic contact member 26b, 27b, 28b and 29b, respectively, which is normally closed with a fixed contact member 260, 27c, 28c and 29c, respectively, and which opens with a delay of 30 seconds after filament enengization. Relays 26, 27, 28 and 29 are commonly available under the designation of 2C30.

In the illustrated case I employ two alarm circuits which are utilized independently to operate alarm devices 30 and 31 which may be located at some remote point such as at an attended control station or which are utilized to transmit a radio signal to such an attended con- The internal connections in cabinet 13 between the 4 1. various terminal posts and relays 24, 25, 26, 27, 28, and 29 are as follows.

Filament 24a is connected between posts 12a and 12d, and filament 25a is connected between posts 12a and 12e. Thus filament 24a is energized upon closure of the circuit through photo-unit 10 and filament 25a is energized as long as power is supplied through lines 8 and 9 and circuit breaker 11 is closed. Filament 26a is connected between terminal posts 12c and 12 and thus is energized by a voltage drop produced across adjustable resistor 16. Similarly, filament 27a is connected between terminal posts and 12g for energization by a voltage drop across adjustable resistor 17; filament 28a is connected between terminal posts 12d and 12h for en" ergization by a voltage drop produced across adjustable resistor 18; and filament 29a is connected betweenterminal posts 12d and 121' for energization by a voltage drop produced across adjustable resistor 19. Alarm'de vice 30 is connected to neutral line 8 by a connection between terminal post 12:: and terminal post 12 in series with switch contacts 24b and 240 of relay 24 and in series with parallel switch contacts 26b and 26c and switch contacts 27b and 27c of relays 26 and 27. Similarly, alarm device 31 is connected to neutral line 8 by internal connection between terminal post 12a and terminal post 12k which includes in series switch contacts 24b and 24c of relay 24 and in series the parallel combination of switch contacts 28b and 280 and switch contacts 2% and 290 of relays 28' and 29. Switch contacts 25b and 25c of relay 25 are connected between terminal post 12a and terminal post 12k.

In order to illustrate the operation of the device shown in the drawing assume power is continuously supplied to leads 8 and 9 and circuit breaker 11 is properly closed. Relay 25 is thus actuated with switch contacts 25b and 250 held open. As daylight fails, photo-unit 10 closes the main circuits to beacon lamps 2 and 3 through flasher unit 15 and the main circuits to side lamps 4, 5, 6 and 7, thus lighting all six lamps on tower 1.

As photo-unit 10 operates, filament 24a is energized and contact 24b begins to move toward contact 246. Closing these contacts requires a period of approximately two minutes. In the meantime, filaments 26a, 27a, 28a and 29a are also energized by the voltage drop produced in resistors 16, 17, 18 and 19, respectively, by the flow of. current therethrough to the various lamps on tower 1. The consequent actuation of relays 26, 27, 28 and 29 causes bi-m-etallic contact members 26b, 27b, 28b and 2%, respectively, to part from fixed contact members 26c, 27c, 28c and 290, respectively, within a period of relatively short duration, i. e. 30 seconds, thus opening alarm circuit 33 (through relays 26 and 27) and alarm circuit 34 (through relays 28 and 29) so that, by the time relay 24 has closed, the alarm circuits cannot be actuated by such closure and thus a false alarm is not transmitted 'during the warming up period of relays 26, 27, 28 and 29. It should be noted that resistors 16, 17, 18 and 19 are adjusted to provide the required resistance for proper energization of filaments 26a, 27a, 28a and 29a, respectively.

Failure of either beacon lamp 2 or 3 or its associated connection 20 or 21 will eliminate the voltage drop produced in resistor 16 or 17, respectively, and consequently cause de-energization of either relay 26 or 27, depending upon which beacon lamp has failed. Since relay 24 is closed such deactuation of either relay 26.01- 27 will energize alarm circuit 33 and thus produce an alarm at device 30 which will inform the remotely stationed attendant that one of the beacon lamps has failed.

Similarly, failure of one of the side lamps 4 or 5 or of one of the side lamps 6 or 7 will de-energize either relay 28 or 29 and thus close alarm circuit 34 to cause alarm device 31 to operate.

If an overload occurs causing circuit breaker 11 to open, all the relays will become *de-energized and alarm circuit 34 will be energized through the closure of the switch contacts in relay 25, consequently causing alarm device 31 to operate even though the switch contacts in relay 24 open, breaking the alarm circuits through relays 26, 27, 28 and 29.

From the foregoing discussion it will be seen that the device illustrated in the drawing is readily adaptable to other types of remotely located electrical devices which are automatically and intermittently or periodically actuated and is further capable of providing the necessary alarm signals to inform a remotely stationed attendant of such failure. At the same time the device is provided with necessary precautions, to prevent accidental alarms during warm up and is also provided with suitable circuitry to provide actuation of an alarming device in the event the power applied to the remote location should fail.

I claim:

1. In a radio tower having a beacon lamp, a powering circuit, and a photo-electric actuating device and a flashing unit connected in series with said beacon lamp in said powering circuit, the improvement which comprises a normally open thermally operated delayed action circuit controlling device, means energizing said normally open device in response to closure of said photo-- electric device to close said normally open device, a normally closed thermally operated delayed action circuit controlling device having a delay period of shorter duration than said first delayed action device, means located apart from said lamp energizing said normally closed device in response to the flow of current in said powering circuit to open said normally closed device, and an alarm circuit including an alarming device connected in series with said delayed action circuit controlling devices.

2. In a radio tower having a beacon lamp, a powering circuit and a photo-electric actuating device and a fiashing unit connected in series with said beacon lamp in said powering circuit, the improvement which comprises a normally open thermally operated delayed action circuit controlling device, means energizing said normally open device in response to closure of said photo-electric device to close said normally open device, a normally closed thermally operated delayed action circuit controlling device having a delay period of shorter duration than said first delayed action device, means located apart from said lamp energizing said normally closed device in response to the flow of current in said powering circuit to open said normally closed device, an alarm circuit including an alarming device connected in series with said delayed action circuit controlling devices, a second normally closed thermally operated delayed action circuit controlling device having a delay period of shorter duration than said normally open delayed action device, and means energizing said second normally closed device in response to energization of said powering circuit to open said second normally closed device, said second normally closed device being connected in said alarm circuit paralleling said normally open delayed action device and said first normally closed delayed action device.

3. In a remotely located installation including an electrically actuated device, a powering circuit therefor, and an automatic circuit controlling device connected in series with said electrically actuated device in said powering circuit, an alarm system for detecting and indicating faulty power circuit closure which comprises a normally open thermally operated delayed action circuit controlling device, means energizing said normally open device in response to closure of said automatic circuit controlling device to close said normally open device, a normally closed thermally operated delayed action circuit controlling device having a delay period of shorter duration than said normally open delayed action device, means located apart from said remotely located electrically actuated device energizing said normally closed device in response to the flow of current in said powering circuit to open said normally closed device and an alarm circuit including an alarming device connected in series with said delayed action circuit controlling devices.

4. In a remotely located installation including an electrically actuated device, a powering circuit therefor, and a first automatic circuit controlling device and a second automatic circuit controlling device connected in series with said electrically actuated device in said powering circuit, said second automatic circuit controlling device being intermittently or periodically operable to close said powering circuit and said first controlling device being operable -to close said powering circuit in response to a varying external condition, an alarm system for detecting and indicating faulty power circuit closure which comprises a normally open thermally operated delayed action circuit controlling device, means energizing said normally open device in response to closure of said first automatic circuit controlling device to close said normally open device, a first normally closed thermally operated delayed action circuit controlling device having a delay period of shorter duration than said normally open delayed action device, means located apart from said remotely located electrically actuated device energizing said normally closed device in response to the flow of current in said powering circuit to open said normally closed device, an alarm circuit including an alarming device connected in series with said delayed action circuit controlling devices, a second normally closed thermally operated delayed action circuit controlling device having a delay period of shorter duration than said normally open delayed action device, and means energizing said second normally closed device in response to energization of said power circuit to open said second normally closed device, said second normally closed device being con-' References Cited in the file of this patent UNITED STATES PATENTS Bassett Apr. 1, 1930 Boddy Jan. 13, 1953 

